The Contractor shall study the effects on the immune response of defined components of group A streptococcal cells and shall determine whether these isolated factors can influence tumorigenesis and tumor growth, and study the mechanisms by which this is accomplished. The effect of the bacterial components shall be related to changes induced in cell mediated and humoral immunity against tumor antigens. The streptococcal components studied shall be the immunosuppressant factor derived from protoplast membranes which has been shown to suppress B cells, and the mucopeptide component of cell walls which has adjuvant activity.